Fuel oil



Patented M'ay 27, 1941 FUELOIL Melvinv A. Dietrich, Claymont, DeL, assignor to E. I. 'du Pont de Nemours & Company, Wilmington, Del., a corporation of Delaware No Drawing. Application January 28, 1939,

Serial No. 253,448

'18 Claims. (Cl. 4H)

This invention relates to non-viscous normally liquid hydrocarbon oils and to processes for improving their properties, and more particularly to the production of fuel oils having improved flow characteristics under low temperature conditions and improved ,wear characteristics.

Non-viscous normally liquid hydrocarbon oils are generally used as fuel oils, particularly in Diesel engines, as furnace oils and as hydraulic fluids in brakes or fluid-driven mechanisms. Such oils generally conform to the following specifications:

These oils are of low molecular weight, that is, they have an average maximum molecular weight of about 250. Accordingly, when I refer to nonviscous normally liquid hydrocarbon oils hereinafter, it will be understood that I mean such oils having a Saybolt Universal viscosity at 100 F. of not over '45 seconds, and preferably those of low molecular weight.

Such non-viscous normally liquid hydrocarbon oils are frequently employed under quite low temperature conditions, but tend to congelate at temperatures of approximately zero to about -5 F. Accordingly, it becomes important to produce oils of this type which will not congeal at temperatures well below --5 F. and which will flow freely and have improved flow characteristics at such low temperatures.

Furthermore, oils of this type which are to be used in internal combustion engines, particularly those of the Diesel type, have a low cetane number and poor combustion characteristics. The addition of paraifin to such oils has been found to raise the cetane number to a material-extent, to improve the viscosity temperature relationship of the oil and to provide smoother flow of oil through pipe lines under varying temperature conditions. Accordingly, it has become established practice to add paraffin wax to such oils for such purposes. In general, the amount of paraifin wax added to the oil is between about 0.1 to 5%, and preferably between 0.1 to 1%.

The non-viscous normally liquid hydrocarbon oils frequently operate in systems which are close fitting and in which the moving parts have little opportunity to be adequately lubricated. This is particularly true of oils used for fuels in internal combustion engines, and especially in compression-ignition engines of the Diesel type. The oil, per se, has substantially no lubricating value, and hence the wear of moving parts in pumps, ejectors and the like constitutes a serious problem. This problem can be largely overcome by imparting lubricating properties to the oil.

It is an object of the present invention to provide non-viscous normally liquid hydrocarbon oils of improved flow characteristics under low temperature conditions and improved wear or lubricating characteristics. Another object is to treat non-viscous normally liquid hydrocarbon oils so as to overcome to a material extent the disadvantages of previously known oils of this type. It is a further object of the present invention toproduce non-viscous normally liquid hydrocarbon oils of improved flow characteristics even in the presence of added paraflin. Still further objects are to provide new compositions of matter, methods of preparing the same and to advance the art. Still other objects will appear hereinafter.

The above andother objects may be accomplished in accordance with my invention which comprises the addition of a hydrogenated castor oil derivative to a non-viscous normally liquid hydrocarbon oil, preferably of low molecular weight. By hydrogenated castor oil derivative as used herein is meant the product obtained by causing hydrogenated castor oil to react either with its own free hydroxyl group or with another organic compound selected from the classes of alcohols, aldehydes, acids, isocyanates, and isothiocyanates at temperatures between about ,80 F. and about 550 F. and in the presence or absence of a catalyst. Preferably, the compound reacted with the hydrogenated castor oil contains F. and 160 F., and preferably between about F. and about F. The time of heat treatment of the hydrogenated castor oil, either in the presence or absence of a catalyst, may be varied over wide limits but may generally be expected to be from about two to about eight hours in the presence of a catalyst and from about 16 to about 64 hours in the absence of a catalyst. Also, as is usual, the time of heat treatwith another material containing an alcoholic depressing the pour point of a paraflin base fuel oil as indicated by the following table:

Pour point F. Fuel oiluntreated -5 Fuel oil+0.5% hydrogenated castor oil hydroxyl group, it is generally necessary to employ temperatures of from about 330 to about 550 F., and preferably temperatures of about 390 to about 410 F. When other modifying agents are employed, lower temperatures will ordinarily be used. In any event, the temperature and time of treatment must be chosen so as to produce a soft wax for the most effective product. Hard waxes and liquid products are ineffective or substantially so. Waxes which soften between about 70 F. and 160 F. are effective.

Within the scope of the term alcohols" as employed herein and in the claims, it will be understood that I intend to include hydrogenated castor oil also since it still contains the secondary hydroxyl group originally present in the castor oil. In fact, the products obtained by the simple heat treatment of the hydrogenated castor oil in the presence orabsence of a catalyst constitute the preferred embodiments of my invention.

The catalyst to be employed should be an ester interchange catalyst such as the alkali metals, alkali metal alkoxides, alkaline earth metal oxides, lead oxide, tin oxide, aluminum oxide, chromium oxide and nickel oxide and compounds of the type represented by benzene sulfonyl chloride. Of these, the preferred catalysts are lead oxide and tin oxide.

The concentration of the hydrogenated castor oil derivative to be employed in the oil will be determined by the properties desired in the fin ished product and by the amount of parafiin originally present or added to the oil. Generally, quantities varying from 0.3% to 0.6% will be effective in producing desirablecharacteristics in the oil. However, one may employ as little as 0.1% or as much as 2% or more, if necessary.

As has been pointed out heretofore, the addition of parafiin wax to such non-viscous normally liquid hydrocarbon oils has a disadvantage of raising the pour point, resulting in congelation at relatively high temperatures. I have found, however, that when the hydrogenated castor oil derivatives of my invention are added to oils containing small amounts of added paraffin, the resulting product has a very low pour point. The addition of the paraffin appears to have but very little effect upon the pour point in the presence of the compounds of my invention. However, I have not found my compounds to have a deleterious effect upon the desirable properties of the paraffin.

In the preparation of the various derivatives described below, a hydrogenated castor oil was used which conformed to the following approximate characteristics: melting point, 171 F. to 178 F.; acid number, 2.0 mg. potassium hydroxide per gram of wax; saponification number. 180 mg. potassium hydroxide per gram of wax; iodine absorption, 30 mg. iodine per gram of wax. This material, per se, had a negligible effect in The characteristics or this fuel il; also used in the following examples, are as follows:

Gravity at 60 F./60 F A. P. I 27.5 Viscosity at 100 F.Saybolt Universal seconds 38.9

Initial boiling/point; F 365 10%-distillation point"; 439 20% distillation point F 475 r 40% distillation point F 511 60% distillation point F 552 80% distillation point 626 90% distillation point F 666 97% distillation point (maximum temperature) .F 698 The hydrogenated castor oil was heated to 392 F. for two hours with 1% lead oxide. The product was a soft wax having the following characteristics: softening point, 131 F.-149 F.; iodine absorption, 45 mg. iodine per gram of oil; acid number, 6.2 mg. potassium hydroxide per gram of oil; hydroxyl number, mg. potassium hydroxide per gram of oil. This material added to the previously mentioned fuel oil of -5 F. pour-point gave the following results:

Percent by weight of mod- Pour-point ifying agent F. 0.3 Below --35. 0.5 Below 35.

The presence of paraflin wax is highly desire able in a fuel oil for Diesel engines from the standpoint of improved viscosity and combustion characteristics (as measured by cetane number). The addition of paraffin wax is accompanied, however, by an undesirable increase in pour-point with resultant poor flow characteristics at low temperatures. The effect of the heatmodified hydrogenated castor oil on such a waxbearing fuel oil is shown by the following data:

Pour point F. Fuel oil plus 0.3% commercial paraffin wax +5 Above plus 0.5% heat-modified hydrogenated castor oil below 40 Example 2 Equimolecular quantities of hydrogenated castor oil and adipic acid were heated for three hours at 392 F. The resulting material was a soft wax which in 0.5% concentration in fuel oil resulted in a product having a pour-point lower than -35 F.

Example '3 Example 4 Nineteen grams of hydrogenated castoroil was mixed with 100 cc. benzene and 14 grams of phenyl isocyanate were added. The resulting mixture was heated 15 hours on a steam bath at 100 F. to 125 F., washed with water, dried over sodium sulfate and the solvent removed by evaporation. A pale brown soft wax was recovered which contained .2.6 'per cent nitrogen. This material, in 0.5% concentration in the fuel oil, yielded a product with a pour-point below 35" F.

Example Ten grams of hydrogenated castor oil was dissolved in 100 cc. benzene and 7 grams of decamethylene diisocyanate were added. The solution was refluxed for 5 hours and the solvent then removed by evaporation. The resulting product was a light yellow wax, 0.5 per cent of which lowered the pour-point of the fuel to below -35 F.

The above examples are illustrative only. Similarly effective products may be made by reacting the hydrogenated castor oil with aldehydes such as 2-ethylhexenal or with isothiocyanates such as decamethylene diisothiocyanate. Many other alcohols, aldehydes, acids, isocyanates, and isothiocyanates will be readily apparent to those skilled in the art. The isocyanates and isothiocyanates containing aliphatic, cycloaliphatic, or aryl groups are suitable. The compounds to be reacted with the castor oil need not be pure materials but may be mixtures. For example, I may use alcohols derived from the hydrogenation of carbon oxides or aldehydes and acids secured by the oxidation of these alcohols; naphthenyl alcohols, naphthenyl acids, terpene alcohols, fenchyl alcohol, straight or branched chain alcohols or acids derived from oxidation of petroleum and alcohols or acids derived by the hydrogenation of animal and vegetable oils.-

Similar products may be produced by reacting with the hydrogenated castor oil, thiols, such as dodecyl thiol, and ketones, such as methyl ethyl ketone.

In the above examples, the derivatives were prepared from a certain hydrogenated castor oil. Castor oil hydrogenated to a different extent may be employed but it is generally preferable to employ a hydrogenated castor oil having a softening point of at least 150 F. and particularly castor oil which has been substantially completely hydrogenated.

In the examples given above, the modifying treatment has been applied to castor oil after hydrogenation. In the case of the simple heat treatment either in the absence or in the presence of a catalyst and in the case of the other reaction materials, products of substantially the same general characteristics may be secured by reacting the castor oil itself with the modifying agents and then hydrogenating the resulting products. Alternatively, products, functioning similarly, could be secured by dissolving the materials in the hydrocarbon oil and causin them to react by the application of catalysts and heat.

However, such alternative processes are not subject to easy control to produce products havin the necessary properties to produce the maximum effect on the oil.

It will thus be apparent that by my invention 1 have provided non-viscous normally liquid hydrocarbon oils with improved flow characteristics at low temperatures and reduced wear tendencies toward moving parts. Furthermore, since paraffin may be added to such oils more freely in the presence of my compounds, it is possible in accordance with my invention to provide fuel oils for internal combustion engines having more satisfactory combustion characteristics and better viscosity temperature characteristics over the operating temperature ranges.

In view of the above description wherein the preferred embodiments of my invention and the preferred modes of carrying the same into effect have been disclosed, it will be readily apparent to those skilled in the art that many variations and modifications may be made therein without departing from the spirit of my invention. Accordingly, the scope of my invention is to be limited solely by the appended claims construed as broadly as is permissible in view of the prior art.

I claim:

1. A non-viscous normally liquid hydrocarbon fuel oil having incorporated therein a small amount of a hydrogenated castor oil derivative having a softening point between about 70 F. and about F., said hydrogenated castor oil derivative being the product of the reaction of hydrogenated castor oil with an organic compound selected from the class consisting of alcohols, aldehydes, isocyanates and isothiocyanates, the amount of the'hydrogenated castor oil derivative being in the range offrom 0.1% toabout 2% and sufficient to materially decrease thepour point of the oil and impart lubricating characteristics to the oil.

2. A non-viscous normally liquid hydrocarbon fuel oil having incorporated therein a. small amount of a hydrogenated castor oil derivative having a softening point between about 70 F. and. about 160 F., said hydrogenated castor oil derivative being the product of the reaction of hydrogenated castor oil with an alcohol contain ing at least 6 carbon atoms, the amount of the hydrogenated castor oil derivative being in the range of from 0.1% to about 2%and sufiicient to materially decrease the pour point of the oil and impart lubricating characteristics to the oil.

3. A non-viscous normally liquid hydrocarbon fuel oil having incorporated therein a small amount of a hydrogenated castor oil derivative having a softening point between about 70 F. and about 160 F., said hydrogenated castor oil derivative being the product obtained by heating the hydrogenated castor oil at temperatures of about 330 F. to about 550 F., the amount of the hydrogenated castor oil derivative being in the range of from 0.1% to about 2% and sufiicient to materially decrease the pour point of the oil and impart lubricating characteristics to the oil. a 4. A non-viscous normally liquid hydrocarbon fuel oil having incorporated therein a small amount of a hydrogenated castor oil derivative having a softening point between about 70 F.

and about 160 F., said hydrogenated castor oil derivative being the product obtained by heating hydrogenated castor oil to between about 330 F. and about 550 F. in the presence of an alkaline catalyst, the amount of the hydrogenated castor oil derivative being in the range of from 0.1% to about 2% and sufficient to materially decrease the pour point of the oil and impart lubricating characteristics to the oil.

5. A non-viscous normally-liquid hydrocarbon fuel oil having incorporated therein a small amount of a hydrogenated castor oil derivative having a softening point between about 70 F. and about 160 F., said hydrogenated castor oil derivative being the product obtained by heating hydrogenated castor oil to between about 390 F. and about 410 F. in the presence of an alkaline catalyst, the amount of the hydrogenated castor oil derivative being in the range of from 0.1% to about 2% and suflicient to materially decrease the pour point of the oil and impart lubricating characteristics to the oil.

6. A non-viscous normally liquid hydrocarbon fuel oil having incorporated therein a small amount of a hydrogenated castor oil derivative having a softening point between about 70 F.

and about 160 F., said hydrogenated castor oil amount of a hydrogenated castor oil derivative having a softening point between about 70 F. and about 160 F., said hydrogenated castor oil derivative being the product of the reaction of hydrogenated castor oil with decamethylene diisocyanate, the amount of the hydrogenated castor oil derivative being in the range of from 0.1% to about 2% and suflicient to materially decrease the pour point of the oil and impart lubricating characteristics to the oil.

8. A non-viscous normally liquid hydrocarbon fuel oil having incorporated therein a small amount of a hydrogenated castor oil derivative having a softening point between about 70 F. and about 160 said hydrogenated castor oil derivative being the product of the reaction of hydrogenated castor oil with an organic compound containing at least 6 carbon atoms selected from the class consisting of alcohols, aldehydes, acids, isocyanates and isothiocyanates in the presence of a catalyst selected from the group consisting of alkali metals, alkali metal alkoxides, alkaline earth oxides, lead oxide, tin

oxide, aluminum oxide, chromium oxide, nickel oxide and ester interchange catalysts of the type of benzene sulfonyl chloride, the amount of the hydrogenated castor oil derivative being in the range of from 0.1% to about 2% and suflicient to materially decrease the pour point of the oil and impart lubricating characteristics to the oil.

9. A non-viscous normally liquid hydrocarbon fuel oil having incorporated therein a small amount of a hydrogenated castor oil derivative having a softening point between about 70 F.

and about 160 F., said hydrogenated castor oil derivative being obtained by heating the hydrogenated castor oil at temperatures of about 330 F. to about 550 F. in the presence of a catalyst selected from the group consisting of alkali metals, alkali metal alkoxides, alkaline earth oxides, lead oxide, tin oxide, aluminum oxide,

chromium oxide, nickel oxide and ester inter change catalysts of the type of benzene sulfonyl chloride, the amount of the hydrogenated castor oil derivative being in the range of from 0.1% to about 2% and sufficient to materially decrease the pour point ofthe oil and impart lubricating characteristics to the oil.

10. A non-viscous normally liquid hydrocarbon fuel oil having incorporated therein a small amount of a hydrogenated castor oil derivative having a softening point between about F. and about 160 F., said hydrogenated castor oil derivative being the product of the reaction of hydrogenated castor oil with an organic compound containing at least 6 carbon atoms selected from the class consisting of alcohols, aldehydes, acids, isocyanates and isothiocyanates in the presence of lead oxide at temperatures between F. and about 550 F.'for a: sufficient length of time to modify the hydrogenated castor oil so that it has a softening point between about 70 F. and about F., the amount of the hydrogenated castor oil derivative being in the range of from 0.1% to about 2% and suflicient to materially decrease the pour point of the oil and impart lubricating characteristics to the oil.

11. A non-viscous normally liquid hydrocarbon fuel oil having incorporated therein a small amount of a hydrogenated castor oil derivative having a softening point between about 70 F. and about 160 F., said hydrogenated castor oil derivative being obtained by heating the hydrogenated castor oil at temperatures of about 330 F. to about 550 F. in the presence of lead oxide, the amount of the hydrogenated castor oil derivative being in the range of from 0.1% to about 2% and sufiicient to materially decrease the pour point of the oil and impart lubricating characteristics to the oil.

12. A non-viscous normally liquid hydrocarbon fuel oil having incorporated therein a small amount of paraflin and a small amount of a hydrogenated castor oil derivative having a.

softening point between about 70 F. and about 160 F., said hydrogenated castor oil derivative being the product of the reaction of hydrogenated castor oil with an organic compound selected from the class consisting of alcohols, aldehydes, acids, isocyanates and isothiocyanates, the amount of thehydrogenated castor oil derivative being in the range of from 0.1% to about 2% and sufllcient to materially decrease the pour point of the oil and impart lubricating characteristics to the oil.

13. A non-viscous normally liquid hydrocarbon fuel oil having incorporated therein a small amount of paraffin and a small amount of a hydrogenated castor oil derivative having a softening point between about 70 F. and about 160 F., said hydrogenated castor oil derivative being the product of the reaction of hydrogenated castor oil with an alcohol containing at least 6 carbon atoms, the amount of the hydrogenated castor oil derivative being in the range of from 0.1% to about 2% and sufficient to materially decrease the pour point of the oil and impart lubricating characteristics to the oil.

14. A non-viscous normally liquid hydrocarbon fuel oil having incorporated therein a small amount of paraflin and a small amount of a hydrogenated castor oil derivative having a softening point between about 70 F. and about 160 F., said hydrogenated castor oil derivative being the product obtained by heating the hydrogenated castor oil at temperatures of about 330 castor oil with an isocyanate containing at least 6 carbon atoms, the amount of the hydrogenated castor'oil derivative being in the range of from 0.1% to about 2% and sufficient to materially decrease the pour point of the oil and impart lubricating characteristics to the oil.

16. A non-viscous normally liquid hydrocarbon fuel oil having incorporated therein a small amount of paraifin and a small amount of a hydrogenated castor oil derivative having a softening point between about 70 F., and about 160 F., said hydrogenated castor oil derivative being the product of the reaction of hydrogenated castor oil with an organic compound containing at least 6 carbon atoms selected from the class consisting of alcohols, aldehydes, acids, isocyanates and isothiocyanates in the presence of a .catalyst selected from the group consisting of alkali metals, alkali metal alkoxides, alkaline earth oxides, lead oxide, tin oxide, aluminum oxide, chromium oxide, nickel oxide and ester interchange catalysts of the type of benzene sulfonyl chloride, the amount of the hydrogenated castor oil derivative being in the range of from 0.1% to about 2% and sufficient to materially decrease the pour point of the oil and impart lubricating characteristics to the oil.

17. A non-viscous normally liquid hydrocarbon fuel oil having incorporated therein a small amount of a hydrogenated castor oil derivative having a softening point between about 70 F. and about 160 F., said hydrogenated castor oil derivative being the product of the reaction of hydrogenated castor oil with an organic acid containing at least 6 carbon atoms, the amount of the hydrogenated castor oil derivative being in the range of from 0.1% to about 2% and sulficient to materially decrease the pour point of the oil and impart lubricating characteristics to the oil.

18. A non-viscous normally liquid hydrocarbon fuel oil having [incorporated therein a small amount of a hydrogenated castor oil derivative having a softening point between about 70 F. and about 160 F., said hydrogenated castor oil derivative being the product of the reaction of hydrogenated castor oil with adipic acid, the amount of the hydrogenated castor oil derivative being in the range of from 0.1% to about 2% and sufficient to materially decrease the pour point of the oil and impart lubricating characteristics to the oil.

MELVIN A. DIETRICH.

CERTIFICATE OF CORRECTION.

Patent No. 2,245,198. May 27, 191,11.

MELVIN A. DIETRICH.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 5, sec- 0nd column, line 59, before "isocyanates" insert the word and come .--acids,-; and that the said Letters Patent shouldbe read vwith this correction therein that the same may conjorm to the record of the case in the Patent Office.

Signed and sealed this lst day of July, A. D. 19m.

Henry Van Arsdale, (Seal) Acting Commissioner of Paten 

